Image processing device and image processing method

ABSTRACT

Games are processed in a more realistic and immediate manner during image processing for soccer games and the like. Specifically, the movements of characters more accurately simulate those of actual opponents, resulting in greater game realism.  
     The invention is an image processing device for imaging and displaying the behavior of characters modeled on opponents in virtual three-dimensional space. It is determined (S 21  to S 24 ) whether or not there exists a certain situation in which the relation to the game contents (in the centering area, for example) or the positional relation (such as distance) between characters and a target (such as opponent characters or the ball) having a relation through the game to said characters matches certain conditions, and the eyes of the characters are directed to the target (S 25,  S 26,  S 28,  etc.) when it is determined that the certain situation exists. The invention is especially suitable for soccer games.

TECHNICAL FIELD

[0001] The present invention relates to an image processing techniquesuitable for use in image processing devices such as TV games in whichcharacters (objects, in the broader sense) are situated in virtual spaceto play a soccer game or the like, and more particularly to an imageprocessing technique for making games seem more realistic and moreimmediate by executing various processes such as control of acharacter's eye direction, control of a character's behavior, and fogprocessing to adjust the colors on the screen. The present inventionalso relates to an image processing technique which provides images thatare easier for players to see by suitably controlling the angle of thevirtual camera relaying the developing situation in a game or theorientation of objects situated in the game field.

BACKGROUND ART

[0002] Progress in recent computer technology has led to the widespreadpopularization of image processing techniques for TV games, simulationdevices, and the like. The sophistication of image processing techniqueswhich more realistically portray display contents and display screens isextremely important in enhancing commercial value.

[0003] The components of TV games, for example, comprise peripherals,including a display monitor and operating instruments such as pads andjoysticks, as well as processors with a CPU that executes imageprocessing, audio processing, data transmission with the peripherals,and so forth, allowing interactive games to be played with suchoperating instruments.

[0004] Game devices allowing soccer games to be played are one of thefields of such TV game machines. In such soccer games, a soccer stadiumwith a field and spectator seats (stands) is commonly constructed inthree-dimensional virtual space, and the characters (referred to asdisplay objects or objects) of two teams play a virtual soccer game onthe field. Specifically, motion is computed according to operating datafrom players, the ball is processed, collisions (hits) are processed,robots are processed, the field is processed, and the like, in sequence,and game development reflecting the manipulation by players is displayedon screen.

[0005] Because the behavior of the spectators in the stands is also animportant element contributing to the game environment at this time, thebehavior of the spectators is also often processed. Examples of methodsfor controlling the behavior of spectators include: 1) methods in whicha great deal of image data of moving spectators is prepared in advancefor each frame, in the same manner as with animation (moving images),and images are mapped with texture according to the competitive scenarioand are displayed in moving images; and 2) methods in which polygonsshowing spectators are prepared, and the polygons are moved according tothe competitive scenario.

[0006] The problem of whether or not the display screen colorationmatches the actual brightness (such as sunlight) over time throughoutthe day is another important element in enhancing the game environmentor immediacy. This is a particularly important feature of soccer gamessince they are often played out-of-doors, and there are subtle changesin the physical environment related to brightness depending on the timezones during the day in which the soccer game is played. In other words,the brightness changes depending on which time zone—morning, afternoon,or evening—in which the game is being played and where in those timeszones the game is being played. A method for adjusting the luminance ofthe color screen according to time zone has been known in the past.

[0007] However, the aforementioned game machine suffers from thefollowing drawbacks in terms of game immediacy and realism.

[0008] First, using soccer games as an example, when characters playagainst each other while dribbling the ball in conventional gamemachines, the characters can dribble only while facing in the directionin which they are running. However, when shooting or passing to a teammate while dribbling in actual soccer games, the athlete that isdribbling looks (looks around) in the same direction in which he isrunning or in other directions in order to plan the timing of kicks orto look for a kicking zone or team mates. That is, it is difficult torealistically simulate the actual behavior of soccer players just bycontrolling running motions while dribbling, and the actions of thecharacters on the display screen are primitive and unnatural. Thecontrol of the direction in which a character is facing (that is, theeye direction) is the same for the player who is running while dribblingas well as for other players who do not have the ball. Home teamcharacters also naturally turn their faces (eye direction) depending onthe actions of the characters of the opposing team, but no such controlhas been managed in the past.

[0009] Second, the behavior of spectators is also an important elementaffecting the immediacy of a game. In the past, however, the varyingmovements of individual spectators (more realistic behavior), simplicityof software design, reduction in computing load, decrease in memorycapacity, and the like have not been satisfactorily achievedsimultaneously.

[0010] In cases where spectators are displayed with animated texturemapping as in the past, the low number of frames showing movementresults in crude and discontinuous spectator movement. The number offrames is increased in an effort to avoid this. As a result, the imagedata that is handled increases, requiring greater memory capacitySoftware design also becomes more complicated, and the computing loadincreases. When the load increases too much, character (or object)control is hindered, resulting in the need to conserve spectator load.However, when spectator control is scaled back for such conservation,the screen that is displayed is not very exciting and lacks immediacy.

[0011] On the other hand, when spectators are displayed with polygons,the number of spectators which can be displayed with polygons isextremely limited when taking into account the burden involved incontrolling them. If the computing load for such control is disregarded,it might be possible to display individual spectators with polygons andto individually control their movement, but that would actually bedifficult for large numbers of spectators. Only specific (selected) mainspectators should be displayed with polygons. In fact, spectators dohave individually different movements, but they sometimes move the samein groups. The main movements of the specific spectators thus lackexcitement and immediacy.

[0012] Third, conventional devices are not able to cope with therequirements of game machines nowadays in terms of controlling thephysical environment relating to the actual brightness during the day.For example, the display screen should match the surrounding environmentof players who enjoy the soccer game while sitting in front of the gamemachine in given time zones throughout the morning, afternoon, orevening. However, when the luminance of the entire screen is merelyadjusted, as in conventional devices, the screen becomes darker as nightapproaches, making it all the more difficult to play.

[0013] Fourth, when games which unfold in virtual three-dimensionalspace are displayed on a screen, the ease of game playability variesdepending on the direction of the camera eye direction by which thevirtual camera relaying the game sees the characters (or objects). Theease of game playability also varies depending on the position of thevirtual camera. The three-dimensional display of objects should beemphasized according to the game development area.

[0014] Fifth, when games in virtual three-dimensional space aredisplayed on a screen, the point of view and position of the virtualcamera should be pulled back to display as much of the game field aspossible on the screen to make it easier for players to play the game.When such processing is managed, the lines and markers indicating therange of the sports game court are narrow as compared the entire virtualspace, and they thus disappear because of the screen resolution. Thickerlines have thus been prepared to prevent such disappearance. However,when the camera zooms up (the point of view approaches the main point ofview) to enhance game excitement, especially thick lines are displayed,which are unnatural.

[0015] In view of the aforementioned problems, an object of the presentinvention is to provide an image processing device and method allowinggames to be processed in a more realistic and immediate manner duringimage processing for soccer games and the like, so as to allow the morerecent requirements of game devices to be adequately dealt with.

[0016] Another object of the present invention is to achieve moreaccurate simulation, so that the movements of the characters are morelike the movements of actual competitors during image processing ofgames such as soccer games, resulting in a more realistic game.

[0017] Yet another object of the present invention is to morerealistically represent the movements of spectators during imageprocessing of games such as soccer games, resulting in far greater gameimmediacy.

[0018] Another object of the present invention is to provide a screen inwhich the color display is adjusted according to the state of the lightsource in the environment of the time zone in which players are actuallyplaying a game during image processing of games such as soccer games,further enhancing game immediacy.

[0019] An object of the present invention is to provide novel means forsuggesting game situations to players based on the actions of moreaccurately simulated characters, and novel means for adjusting theplayability of the game.

[0020] An object of the present invention is to provide a more easilyseen game screen ensuring the display of objects that are necessary tothe players, in such a way that objects which have a specific functionin three-dimensional virtual game space but which tend to disappear inthe conversion to two-dimensional images still remain in thetwo-dimensional game screen even when they are smaller.

[0021] An object of the present invention is to provide an imageprocessing device for controlling the eye direction and direction of thecamera or the position of the virtual camera according to the relativepositional relation between the virtual camera and characters or areasin the game field, and for forming a screen with a more favorableperspective for the player in such areas.

DISCLOSURE OF THE INVENTION

[0022] To achieve the aforementioned objects, the image processingdevice of the present invention is a device that displays the behaviorof characters modeled on opponents in virtual three-dimensional space,comprising determination means for determining whether or not thereexists a certain situation in which the relation to the game contents orthe positional relation (such as distance) between characters and atarget (imaginary point) having a relation through the game to theaforementioned characters matches certain conditions, and eye directioncontrol means for directing the eye direction of the aforementionedcharacters to the aforementioned objects when the determination meanshas determined the aforementioned certain situation exists. Anyimaginary point in virtual space can be used instead of the targetpoint.

[0023] For example, when the aforementioned game is a soccer game, theaforementioned target is a ball in the aforementioned soccer game. Forexample, the aforementioned eye direction control means may includemeans for rotating and controlling the torsos and waists of theaforementioned characters with the rotation of the heads of theaforementioned characters. The aforementioned determination means mayinclude, for example, means for computing the angle from theaforementioned characters to the target based on coordinate values ofthe aforementioned characters and the aforementioned target in theaforementioned virtual three-dimensional space.

[0024] There are preferably a plurality of the aforementioned objects,and the aforementioned determination means preferably includesdetermination means for determining to which of the aforementionedplurality of targets the eye direction should be directed according tothe aforementioned game situation.

[0025] The image processing method of the present invention is a methodfor displaying the behavior of characters modeled on opponents invirtual three-dimensional space, wherein a determination is made as towhether or not there exists a certain situation in which the relation tothe game contents or the positional relation between characters and atarget having a relation through the game to the aforementionedcharacters matches certain conditions, and the eye direction of theaforementioned characters is directed to the aforementioned target whenit has been determined that the certain situation exists.

[0026] In the image processing method of the present invention, adetermination is made as to whether or not certain conditions have beenestablished while the aforementioned character is made to execute afirst behavior, and the aforementioned character is made to execute asecond behavior when the aforementioned certain conditions have beenestablished, so that information on the developing game situation issuggested (or implied) to the player.

[0027] The image processing device of the present invention is a devicefor displaying the behavior of spectators in stands facing the playingfield, comprising a plurality of polygons individually mapped withtextures modeled on a plurality of spectators, the aforementionedplurality of polygons being virtually superposed, and polygonoscillation means for moving the plurality of polygons in the directionsintersecting the directions in which the polygons are superposed.

[0028] The aforementioned plurality of polygons are preferably virtuallysuperposed, while the plurality of polygons that form the variousplurality of objects are interleaved according to the sequence ofobjects, and the aforementioned polygon oscillation means is preferablya means for periodically moving the aforementioned plurality of objectswhile synchronized and linked with each object. The aforementionedmoving direction is preferably the vertical or lateral direction of theaforementioned polygons.

[0029] The image processing method of the present invention is a methodfor displaying the behavior of display spectators in stands facing theplaying field in virtual three-dimensional space, wherein a plurality ofpolygons individually mapped with textures modeled on a plurality ofspectators are virtually superposed, and the aforementioned plurality ofpolygons are moved in directions intersecting the directions in whichthe polygons are superposed.

[0030] The image processing device of the present invention is a devicefor simulating and displaying games in virtual three-dimensional space,comprising sensing means for sensing the time of the aforementioned gamebeing played by a player, and adjusting means for partially orcompletely adjusting the screen colors of the aforementioned imagesaccording to the time sensed by the sensing means. For example, theaforementioned adjusting means may comprise memory means by which dataon predetermined screen color states of at least two standard time zoneswith brightness most suited to the game during the day are stored in theform of various reference values, and data generating means which, whenthe game time sensed by the aforementioned sensing means is withineither of the aforementioned standard time zones, generates masking datafor the game display screen based on the corresponding one of theaforementioned reference values, and which, when the aforementioned timeis not within either of the aforementioned standard time zones,generates the aforementioned masking data based on data for the screencolor state interpolated on the basis of the two reference valuestemporally prior to and following the aforementioned time in theaforementioned at least two reference values.

[0031] The image processing method of the present invention is a methodfor simulating and displaying games in virtual three-dimensional space,wherein the real time during the day in which the player plays theaforementioned game is sensed, and the screen color of theaforementioned images are adjusted according to the real time.

[0032] The image processing device of the present invention is an imageprocessing device for situating objects in virtual space formed by acomputer system, developing a game while controlling the movements ofthe aforementioned objects according to input control and set rules, anddisplaying circumstances in the aforementioned virtual space as thescreen seen from a virtual camera, comprising polygons situated on areference plane serving as the reference in the aforementioned virtualspace, determination means for determining the positional relationbetween the aforementioned polygons and the aforementioned virtualcamera, and polygon tilting means for tilting the aforementionedpolygons, according to the results of the determination, so as toincrease the surface area of the aforementioned polygons seen from theaforementioned virtual camera.

[0033] The aforementioned reference plane is preferably the ground, andthe aforementioned polygons are preferably polygons forming linessituated on the aforementioned ground.

[0034] The aforementioned polygons have a plurality of sides, and theaforementioned polygon tilting means modifies the coordinate values ofthe vertices on one of the sides of mutually facing sides of theaforementioned polygons.

[0035] The image processing device of the present invention is an imageprocessing device for situating objects in virtual space formed by acomputer system, developing a game while controlling the movements ofthe aforementioned objects according to input control and set rules, anddisplaying circumstances in the aforementioned virtual space as thescreen seen from a virtual camera, comprising determination means fordetermining whether or not the aforementioned objects are in a specificarea in the aforementioned virtual space, and camera angle adjustingmeans for adjusting the angle of the aforementioned virtual camera basedon the results of the aforementioned determination.

[0036] The aforementioned camera angle adjusting means preferablyadjusts the angle of the aforementioned virtual camera based on theresults of the aforementioned determination and the direction in whichthe aforementioned objects are moving.

[0037] The aforementioned camera angle adjusting means preferablyadjusts the angle of the aforementioned virtual camera in at least oneof either the lateral and vertical directions in the aforementionedvirtual space.

[0038] The image processing device of the present invention is a devicefor situating objects in virtual space formed by a computer system,developing a game while controlling the movements of the aforementionedobjects according to input control and set rules, and displayingcircumstances in the aforementioned virtual space as the screen seenfrom a virtual camera, comprising determination means for determiningwhether or not the aforementioned objects are in a specific area in theaforementioned virtual space, and zoom adjusting means for adjusting therange of the field of vision of the aforementioned virtual camera basedon the results of the aforementioned determination.

[0039] The image processing device is an image processing device havingan image generating display means for converting virtual spaceconstructed with a three-dimensional model consisting of a plurality ofpolygons to two-dimensional images seen from a virtual camera in anyposition, and displaying them on a display device, comprising anglecomputing means for computing the angle between an eye direction vectorshowing the direction in which the aforementioned virtual camera isfacing (camera eye direction) and a normal line vector showing theorientation of the plane of certain polygons situated in theaforementioned virtual space, and polygon tilting means for changing thecoordinate values of the vertices of the aforementioned polygons, sothat the angle computed by the aforementioned angle computing meansassumes a certain value.

[0040] The image processing device of the present invention is an imageprocessing device having image generating display means for generatingtwo-dimensional images that reveal, from any point of view (or a virtualcamera), virtual space constructed with a three-dimensional modelconsisting of a plurality of polygons, and for displaying them on adisplay device, wherein the aforementioned polygons comprisingnondisappearing polygons which have attributes preventing them fromdisappearing and which contain data for operating a program to preventpolygons from disappearing, the aforementioned disappearance preventionprogram comprises position determination means for determining thepositional relation between the aforementioned nondisappearing polygonsand the aforementioned point of view, and coordinate modification meansfor modifying the coordinate values of the vertices of theaforementioned nondisappearing polygons according to the results of thedetermination by the aforementioned position determination means, andthe aforementioned image processing device furthermore comprisesdisappearance prevention execution means for executing theaforementioned disappearance prevention program when the polygonsvisualized on the aforementioned display device are the aforementionednondisappearing polygons.

[0041] The data recording media of the present invention record aprogram for allowing a computer system to function as any of theaforementioned image processing devices.

BRIEF DESCRIPTION OF THE DRAWINGS

[0042]FIG. 1 is a block diagram depicting the functional structure ofthe game machine in an embodiment of the present invention;

[0043]FIG. 2 is a schematic flow chart outlining the CPU processing;

[0044]FIG. 3 illustrates the angle computation in the control of the eyedirection;

[0045]FIG. 4 illustrates the angle computation in the control of the eyedirection;

[0046]FIG. 5 illustrates the appearance of a character during control ofthe eye direction;;

[0047]FIG. 6 is a schematic flow chart depicting an example of thecontrol of the eye direction;

[0048]FIG. 7 is a schematic flow chart depicting an example of thecontrol of the eye direction along with FIG. 6;

[0049]FIG. 8 illustrates the data structure of the spectator data basedon polygons;

[0050]FIG. 9 is a schematic flow chart depicting an example ofprocessing to control the behavior of spectators;

[0051]FIG. 10 illustrates a frame in an example of the control ofspectator behavior;

[0052]FIG. 11 illustrates another frame in an example of the control ofspectator behavior;

[0053]FIG. 12 illustrates another frame in an example of the control ofspectator behavior;

[0054]FIG. 13 illustrates another frame in an example of the control ofspectator behavior;

[0055]FIG. 14 illustrates another frame in an example of the control ofspectator behavior;

[0056]FIG. 15 illustrates another frame in an example of the control ofspectator behavior;

[0057]FIG. 16 illustrates another frame in an example of the control ofspectator behavior;

[0058]FIG. 17 illustrates another frame in an example of the control ofspectator behavior;

[0059]FIG. 18 is a schematic flow chart relating to an example of fogcontrol;

[0060]FIG. 19 illustrates time zone division for fog control;

[0061]FIG. 20 illustrates an example of a display screen based on fogcontrol;

[0062]FIG. 21 illustrates another example of a display screen based onfog control;

[0063]FIG. 22 is a schematic of an image displayed on a screen as aresult of the control of the eye direction of a character;

[0064]FIG. 23 illustrates an example of the overall structure of a gamedevice;

[0065]FIG. 24 is a block diagram illustrating the circuit structure ofthe game device;

[0066]FIG. 25 illustrates the virtual game space formed by the gamedevice;

[0067]FIG. 26 illustrates the perspective of a line drawn between thecamera position and the ground;

[0068]FIG. 27 illustrates a process in which the vertices on the insideedge of line polygons are elevated to make the line visible;

[0069]FIG. 28 is a flow chart illustrating the process for preventingthe lines from disappearing;

[0070]FIG. 29 illustrates the positional relation between the camera andthe vertices of the line polygons;

[0071]FIG. 30 illustrates the positional relation between the camera andthe vertices of the line polygons;

[0072]FIG. 31 illustrates an example o f the data for the vertices ofthe line polygons;

[0073]FIG. 32a illustrates the movement of a player away from and towardthe viewer;

[0074]FIG. 32b illustrates the direction of the normal line vector ofthe camera at this time;

[0075]FIG. 33a illustrates the lateral movement of a player;

[0076]FIG. 33b illustrates the direction of the eye direction vector ofthe camera at this time;

[0077]FIG. 34a illustrates the lateral movement of a player;

[0078]FIG. 34b illustrates the direction of the eye direction vector ofthe camera at this time;

[0079]FIG. 35 is a flow chart depicting the process for adjusting thelateral angle of the camera;

[0080]FIG. 36 is a continuation of the flow chart illustrating theprocess of adjusting the lateral angle of the camera;

[0081]FIG. 37 illustrates a case in which the main point of view of thecamera is from a player;

[0082]FIG. 38 illustrates and example of the adjustment of the cameraangle when the main point of view is within 8 m of a penalty area;

[0083]FIG. 39 illustrates a case in which the player's progress istoward the viewer;

[0084]FIG. 40 illustrates a case in which the player's progress is awayfrom the viewer;

[0085] FIGS. 41 illustrates an example of the eye direction vector ofthe camera when the player's progress is away from and toward theviewer;

[0086]FIG. 42 illustrates an example of a player moving to the left;

[0087]FIG. 43 illustrates the camera angle adjustment when the playermoves to the left;

[0088]FIG. 44 illustrates an example of the player moving to the right;

[0089]FIG. 45 illustrates the camera angle adjustment when the playermoves to the right;

[0090]FIG. 46 illustrates an example of when the main point of view ofthe camera is from the ball;

[0091]FIG. 47 illustrates an example of the camera angle adjustment whenthe ball and player are separated by at least 15 m;

[0092]FIG. 48 illustrates another example of the camera angle adjustmentwhen the ball and player are separated by at least 15 m;

[0093]FIG. 49 illustrates a case in which the main point of view of thecamera is within 8 m of a penalty area;

[0094]FIG. 50 illustrates the camera angle adjustment when the mainpoint of view of the camera is within 8 m of a penalty area;

[0095]FIG. 51 illustrates a case in which the main point of view is notwithin 8 m of a penalty area;

[0096]FIG. 52 illustrates the camera angle adjustment when the mainpoint of view is not within 8 m of a penalty area;

[0097]FIG. 53 is a flow chart illustrating the vertical angle skiadjustment of the camera;

[0098]FIG. 54 illustrates the vertical angle adjustment of the camera;

[0099]FIG. 55 is a flow chart illustrating the camera zoom adjustment.FIG. 56 illustrates an area in which the player is present on thescreen;

[0100]FIG. 57 is a flow chart illustrating another example of an objectprevented from disappearing;

[0101]FIG. 58 illustrates an object prevented from disappearing;

[0102]FIG. 59 is another example of texture including spectators;

[0103]FIG. 60 is another example thereof;

[0104]FIG. 61 is an embodiment of texture display when polygons mappedwith textures are superposed;

[0105]FIG. 62 is an embodiment for moving polygons; and

[0106]FIG. 63 is another embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

[0107] A first embodiment of the present invention is described belowwith reference to FIGS. 1 through 22, a second embodiment is describedwith reference to FIGS. 23 through 31, and a third embodiment isdescribed with reference to FIGS. 32 through 58. These embodimentsrelate to games integrally incorporating the image processing device ofthe present invention. The application software in these cases assumesoccer game software as an example, but they may similarly beimplemented with other types of software such as that for baseballgames, soft ball games, and basket ball games.

[0108]FIG. 1 schematically illustrates the block structure of the gamedevice pertaining to the first embodiment. The game device has a CPU(central processing unit) 1, with ROM 2, RAM 3, an input device 4, and avideo display processor (VDP) 5 all connected by a bus to this CPU 1.The CPU 1 sequentially executes the game program previously stored inROM 2. The various processes pertaining to the present invention arerealized as the VDP 5 periodically executes the program stored in ROM 2.Three processes relating to the present invention include the process bywhich the sight of line of the characters is controlled, the process bywhich spectator behavior is controlled, and the process of fog controlin the form of display screen color adjustment. In addition to theprogram processed by the CPU 1 or VDP 5, character polygon data as wellas the programs and fixed data necessary for the three processes (suchas spectator polygon data and fog reference data) are previously storedin ROM 2.

[0109] The operating RAM 3 temporarily stores various types of dataduring the execution of the game. The input device 4 is equipped with aninstrument operated by the player, such as a joy stick, and is used toinput the data necessary for executing the game, such as whencontrolling the movement and motions of characters.

[0110] A video RAM (VRAM) 6, imaging device 7, and operating RAM 8 areconnected to the VDP 5. Polygon data from ROM 2 is stored in VRAM 6. Thepolygon data comprises coordinate data for the number of vertices whichare to be displayed and color data given in the form of color palettesfor the vertices. The VDP 5 has a digital signal processor (DSP). Inresponse to periodic timing signals such as the frame switching timing,the VDP 5 actuates and executes an image processing-dedicated programpreviously stored in ROM 2. The coordinates of the polygon data storedin VRAM 6 are converted and processed as a result of processing by theBDP 5, and are transferred to the imaging device 7.

[0111] A texture ROM 9 and frame buffer memory 10 are connected to theimaging device 7. Texture is mapped by the imaging device 7 to thepolygon data which has undergone coordinate conversion, and is writtenin the form of pixel data per frame (screen) to the frame buffer memory10.

[0112] The frame buffer memory 10 is connected by a D/A convertor 11 toan image processing device 12 such as a CRT. The D/A convertor 11functions as a video signal generating circuit, reading pixel data fromthe frame buffer memory 10 and converting it to analog signals. Theconverted data is sequentially sent in the form of video signals to thedisplay device 12, and images are displayed.

[0113] The game device also comprises a fog circuit 13 and real timeclock 14 which are connected to the bus BUS. The real time clock 14 hasa time and calendar function, so as to give real daily time data to theCPU 1. As is described below, the fog circuit 13 has what is referred toas a “fog function,” which involves adjusting the display screen colorthrough masking using specially established color data, referred to asfog data, according to the time in which the game device is operated(that is, the real daily time in which the game device is being playedby a player), and generates fog data under the control of the CPU 1 andtransmits it to the VDP 5.

[0114]FIG. 2 illustrates an example of processing per frame executed bythe CPU 1. First, the CPU 1 receives from the input device 4 charactermotion commands (such as running, turning, and kicking the ball)corresponding to operating data from the player, and computes the motionof characters in three-dimensional virtual space (S1).

[0115] The CPU 1 then processes the ball (S2) in three-dimensionalvirtual space, such as advancing the soccer ball position, and processescollisions (hits) (S3) in three-dimensional virtual space. The collisionprocessing is the determination and processing of various types ofcollisions, such as that between characters and the ground, betweencharacters, and between characters and the ball. The CPU 1 thenprocesses the behavior of the characters (robots) operated by the playerin three-dimensional virtual space in response to operating data fromthe player (S4).

[0116] The CPU 1 also processes the control of the eye direction of thecharacters (S5). This control of the eye direction constitutes acharacteristic feature of the present invention in an effort to providemore diverse character action during the game and to enhance the realismof the soccer game. This process is described in detail below.

[0117] When the process for controlling the eye direction is complete,the CPU 1 processes the soccer game field (S6). This field processinginvolves issuing commands for processes necessary to the game as thepositions of the characters present in the field in virtualthree-dimensional space are used as reference to determine whichcharacters are in the offside line and which characters are in the goalarea so as to advance the game.

[0118] The CPU 1 then processes the control of spectator behavior (S7)and issues commands for fog control (S8). These two processes alsoconstitute part of the characteristic features of the present invention.The process of controlling spectator behavior is an attempt to enhancerealism and immediacy by representing a variety of spectator behaviorswhile suppressing the computing load, and is described in detail below.The process of fog control is an attempt to enhance realism andimmediacy by controlling the brightness of the screen according to thetime throughout the day (color adjustment based on whether the game isplayed during the day or at night) in which the game is actually beingplayed by the player, and is described in detail below. Finally, othernecessary processing is executed (S9).

[0119] Only the main point of view of the character is determined in thecontrol of the point of view in step S5; the motion of actually turninga character may be managed in the subsequent processing time Si. Step S4may be similarly managed. In other words, a timing of at most about 1/60second can be established from the data acquisition and determination ofthe main point of view until the motion is actually carried out in therelevant direction.

[0120] The CPU 1 repeats the aforementioned processing for each frame.Thus, as the game unfolds, the CPU 1 sends commands for motion and thelike corresponding to the manipulations of the player to the VDP 5. Thenecessary polygon data is transferred from the ROM 2 to the VDP 5 underthe control of the CPU 1. The VDP 5 temporarily stores the polygon datain the VRAM 6, the polygon data undergoes coordinate conversion fromvirtual three-dimensional space to perspective two-dimensional spaceaccording to the commands, and the converted coordinates are transferredto the imaging device 7. The imaging device 7 maps texture to thepolygon data that has undergone coordinate conversion and writes it tothe frame buffer memory 10. As a result, images with new pixel data aredisplayed on the display device 12 for each frame.

[0121] The process for the control of the aforementioned character eyedirection is described below with reference to FIGS. 3 through 7. Thisprocess is the step executed in step S5 in FIG. 2.

[0122] The principles of angle computation determining the direction ofthe eye direction of a character C are described first. Here, thecharacter C is assumed to be located at coordinates (Xp, Yp, Zp) inthree-dimensional virtual space, and the soccer ball B serving as thetarget is located at coordinates (Xt, Yt, Zt) in the same space. In thiscase, based on the geometry viewed from the direction of the Y axis inFIG. 3, the following values can be calculated:

i X′=Xt−Xp

Z′=Zt−Zp

[0123] and the angle θy and distance L on the X-Z plane between thecharacter C and the ball B can be calculated from the values X′ and Z′.Similarly, the distance L between the character C and the ball B on thehorizontal axis can be obtained based on this geometry, and the geometryobtained when the vertical axis is the Y axis can be imagined asdepicted in FIG. 4. In other words, the coordinates (Yp, Lp) for thecharacter C and the coordinates (Yt, Lt).for the ball B can bedetermined. In this case, the values

Y′=Yt−Lt

L′=Lt−Lp

[0124] can be calculated, and the angle θy at which the character C seesthe ball B on the Y-L plane can be calculated based on Y′ and L′. Inother words, the eye direction when each character looks at the ball,for example, is determined by the parameters θy, L, and θx. The targetis not limited to the ball, and can be similarly calculated when anotherplayer, the goal, or referee. In other words, it may be managed bygiving the coordinates of one's own character and the coordinates of agiven point for another player or referee or the coordinates of acentral position such as of a goal.

[0125] The direction of the eyes is determined in this manner, but thecharacter's body faces in a variety of directions (way of turning) whilehis eyes are directed in that direction. FIG. 5 illustrates this. In thepresent embodiment, the head HD, torso BD, and waist HP of the characterC are given as components where the body turns (rotates) during thecontrol of the eye direction. Thus, modes of turning such as

[0126]1) when the head HD turns first (vertical or lateral turn), thetorso BD then turns, and the waist HP then turns;

[0127]2) when the head HD and torso BD first turn simultaneously, andthe waist HP then turns; and

[0128]3) when only the torso HD turns

[0129] can be controlled for each situation in which the character issituated for each game scenario. This control may be managed, forexample, by storing the angle to which each part HD, BD, and HP turnsper frame, giving commands for motion based on a slight increase in theangle of the current turning angle in subsequent frames, and terminatingthe turning motion commands at the frame where the calculated angles θxand θy are reached for each body part.

[0130] In general, the movements of the human body are based on naturalstructural principles, and body movements appear most natural if thesenatural principles are applied when characters are set in motion. Forexample, when a body is turned, as indicated in FIG. 5, the neck turnsthe most rapidly, followed by the upper half of the body, and lastly bythe entire body. Thus, when a body is turned, the neck should turnfaster than the upper half of the body, and the upper half of the bodyshould turn faster than the whole body.

[0131] By having the torso BD begin to turn when the turning angle ofthe head HD reaches a certain value, the turning body may be representedas the turning timings of the head, torso, and waist are staggered.

[0132]FIGS. 6 and 7 depict an example of the process for controlling theeye direction determined in this manner. The procedure for controllingthe character eye direction can assume various forms. What is shown hereis only an example, and the present invention is in no way limited tothe examples. The process of controlling the eye direction may becarried out for all competitors (characters) on the field, or it may becarried out for only characters in a designated visual field toalleviate the computing load. It may even be carried out for onlyspecific characters within the designated visual field, such ascharacters of particular concern (for example, characters in motionrelated to the ball or characters under the control of the player(individual playing the game device)).

[0133] As indicated in FIG. 5, for example, it is determined whether ornot a given character is currently running, either YES (running) or NO(not running) (S21). If YES, it is furthermore determined whether or notthe other team has the ball (S22). If the determination is YES (theother team has the ball), it is further determined whether or not acharacter on the other team is dribbling (S23). If YES (is dribbling),it is determined on the basis of the calculated distance values whetheror not the dribbling character is within 3 meters (S24). If YES (within3 meters), the eye direction of the character currently being controlledis directed toward the ball (S25). In the process of step 25, theturning process in FIG. 5 above is added. For example, since thecharacter in step 25 is running, turning mode 1) is suitable, forexample, in directing the character's eye direction to the ball whilerunning.

[0134] If NO (not within 3 meters) in step S24, the eye direction of thecharacter currently being controlled is directed to the character thatis dribbling (S26). The turning control at this time may be in any ofthe forms described with reference to FIG. 5, and should be selectedaccording to the type of angle relation with the other character at thistime.

[0135] If NO (not dribbling) in step S23, and if NO (opposing team doesnot have the ball) in step S22, it is determined whether or not thecurrent ball behavior is a “high ball” (S27). Here, a “high ball” iswhen the ball position is higher than the heads of the characters. IfYES (high ball), a command is given to the character currently beingcontrolled to direct his eyes to the ball (S28). On the other hand, ifNO (not a high ball), the eye direction is not controlled, and themotion-dependent eye direction is maintained (S29). For example, sincethe character is at least running, the eyes are kept in the direction inwhich the character is running. “Motion dependent” means when the eyedirection is not controlled and the movement of the character's actionpattern (motion) determined by the program is used without furthermodification.

[0136] If NO in step S21, that is, when it has been determined thatone's own character is not running, it is sequentially determinedwhether the character is dribbling (FIG. 7, S30) or is in the centeringarea (S31). If YES in step 31, since the character is dribbling and isin the centering area, the character will naturally aim at the goal. Inthis case, the character's eyes are directed at the goal (S32).

[0137] When the character is not in the centering ring in step S31, thecharacter's eyes are directed to the top athlete at a rate of once every4 seconds (S33), for example, and the character's eyes are directed tothe goal at a rate of once every 4 seconds (S34). If NO (not dribbling)in step S30, it is determined whether or not the game is in set play(S35). If YES (set play), it is determined whether or not anothercharacter has decided to pass and is ready to kick (S37), and if YES,the eye direction is directed to the passing character (S37), whereas ifNO, a motion-dependent eye direction is maintained without any specialcontrol of the eye direction (S38).

[0138]FIG. 22 schematically depicts a screen displaying the results ofthe control of a character's eye direction. In the figure, athlete Adirects his line of vision in the direction of athlete B (feet) who isthe passing character. Athlete B directs his line of vision in thedirection of the ball to be passed.

[0139] Controlling the character's eye direction in this manner allowsthe sports behavior of actual soccer games to be simulated far moreclosely. The eye direction is not longer the kind in which the ball issuddenly kicked in another direction while the character is facing thedirection in which he is running, for example, as in the past. In suchcases as well, the character's eyes are first directed in the directionof the kick or the intended kick, so the character's behavior can bemore realistically portrayed, and a more exciting game device withbetter immediacy can be provided. Furthermore, when the eye direction isbeing controlled, not only the head is turned, but the torso or waistare also turned, either consecutively or simultaneously, as needed,allowing the behavior during the control of the eye direction to berealized in a more realistic manner.

[0140] Another advantage of the aforementioned control of the eyedirection is that the direction in which the character's eyes aredirected itself gives clues (suggests) to the player (individual playingthe game device) what the character's next move will be. For example,when a dribbling character begins to direct his eyes frequently behind,it may be concluded that a character from the other team is approachingfrom behind, allowing the player (individual playing the game device) toavoid pursuit. The behavior of the characters can thus telegraph(suggest) situations in the game to the player (individual playing thegame device).

[0141] Conversely, it is possible to make misleading suggestions in thedetermination steps in FIGS. 6 and 7. In other words, the eye directioncan be deliberately directed in a direction completely different fromthe actual determination. This can confuse the judgment of the player(individual playing the game device), can further enhance the interestand excitement of the game device, and can increase the game difficulty.

[0142] The process of controlling spectator behavior is described belowwith reference to FIGS. 8 through 170

[0143] The structure of the image data (spectator data) for portrayingthe spectators in the present invention is described first withreference to FIG. 8. First, spectators are sitting in stands in which m(>2) columns of seats are increasingly higher the further back thestands go, and the spectators in these m columns are divided into n (>2)rows. of these “m columns×n rows,” “m′ columns×n rows” of spectators perm′ column (>0) are represented by mapping textures containing aplurality of spectators onto each rectangular polygon. For example, FIG.8 shows the data structure in virtual space, where A through D, A′through D′, and A″ through D″ indicate 12 rectangular polygons, and thepolygons are layered based on a pattern which is increasingly higher inthe depthwise direction of the stands. Each of polygons A through D, A′through D′, and A″ through D″ is a single polygon, representing aplurality of spectators in 3 column (=m′)×4 row (=n) portions, forexample. The second polygon B located in virtual space behind (depthwisedirection) the first polygon A assumes an initial state that is onecolumn higher, for example, the third polygon C assumes an initial statethat is one column higher, for example, and the fourth polygon D assumesan initial state that is one column higher, for example. As such, “14columns×4 rows” of spectators, for example, are ranked in the stands bymeans of the 12 polygons A through D, A′ through D′, and A″ through D″.

[0144] The first four polygons A through D, for example, among the 12polygons A through D, A′ through D′, and A″ through D″ are mutuallyconnected in a spectator pattern, the next four polygons A′ through D′are mutually connected in a spectator pattern, and the last fourpolygons All through D″ are mutually connected in a spectator pattern.At the same time, three polygons—the first, fifth, and ninth polygons A,A′, and A″—among the 12 polygons A through D, A′ through D′, and A″through D″ constitute one object OB1 in which they move in the samemanner. Similarly, another three polygons—the second, sixth, and tenthpolygons B, B′, and B″—constitute one object OB2 in which they move inthe same manner. Another three polygons—the third, seventh, and eleventhpolygons C, C′, and C″—similarly constitute one object OB3, and anotherthree polygons—the fourth, eighth, and twelfth polygons D, D′, andD″—constitute one object OB4. The spectator patterns of each object arenot connected. That is, a characteristic feature of the spectator datain the present invention is that a plurality of polygons constitute oneobject while separated form each other in virtual space. The spectatorpatterns of each object need not be connected.

[0145] The process of controlling spectator behavior shown in FIG. 9 isexecuted by the CPU 1 using the data structured in this manner. That is,the CPU 1 determines the polygon groups whose behavior is controlledamong all of the spectator data polygons (S41). Thus, any group ofspectator polygons (such as the 12 polygons A through D, A′ through D′,and A″ through D″ in FIG. 10) ranked on the side of the team whom theyare cheering, for example, may be selected from among the spectatorsseen from the virtual camera (point of view). A plurality of polygongroups may also be selected, of course.

[0146] The CPU 1 then selects a behavior pattern to move the determined(selected) polygon groups (S42). Patterns in which one or several groupsof polygons are moved up and down (vertically) or side to side(laterally) have been prepared as behavior patterns. When the behaviorpattern is selected, the CPU 1 executes the process for moving the oneor more groups of polygons according to the selected behavior pattern(S43 a through S43 n).

[0147]FIGS. 10 through 17 depicts examples of ways to move the polygons.The polygon group in these figures is an example of one group and hasthe same data structure as in FIG. 8. FIG. 10 shows the state before thepolygons are moved, and the state sequentially changes frame by frame tothe states of the polygon positions shown in FIGS. 11, 12, 13, 14, 15,and 16, returning after several frames to the state of the polygonpositions shown in FIG. 17 (same as FIG. 10).

[0148] Specifically, in the first new frame shown in FIG. 11, The firstfifth, and ninth polygons A, A′, and A″ from the front constituting thefirst object OB1 are raised up in virtual space (up). In the next newframe shown in FIG. 12, the three polygons A, A′, and A″ of object OB1are raised further up (up), and the second, sixth, and tenth polygons B,B′, and B″ constituting the second object OB2 are raised up (up). In thenext new frame depicted in FIG. 13, the polygons A, A′, and A″ of theobject OB1 drop down in virtual space (down), the polygons B, B′, and B″of the second object OB2 are raised further up, and the third, seventh,and eleventh polygons C, C′, and C″ constituting the third object OB3are raised up (up). In the next new frame depicted in FIG. 14, thepolygons B, B′, and B″ of the second object OB2 and the polygons C, C′,and C″ of the third object OB3 drop down (down), and the three polygonsD, D′, and D″ of object OB4 are raised up (up). In the next new framedepicted in FIG. 15, the polygons c, C′, and C″ of the third object OB3and the polygons D, D′, and D″ of object OB4 drop down (down). In thenext new frame, the polygons D, D′, and D″ of object OB4 which dropsdown more slowly drops further down (down). Thus, as shown in FIG. 17,the sequence returns to the initial state of the polygon positions. Thepolygons may similarly be moved side to side.

[0149] The spectator data of the portion seen from the virtual camera isdesignated by the CPU 1 to the VDP 5 each time one or more groups ofpolygons are moved (from the state in FIG. 10 to that in FIG. 11, forexample) (S44). The process subsequently returns to the process in stepS41, repeating the aforementioned behavior pattern control process foreach new frame. This process for controlling the behavior of thespectators can be executed for groups of display frames instead offrame-by-frame to simplify the process. The process for controllingspectator behavior may also be executed during certain modes (such asduring goals). The display objects in three-dimensional virtual spaceare displayed with changing perspective, relative to the display screen,from a certain point of view of the virtual camera in virtual space(which can be moved by the individual playing the game device). Just tobe sure, the point of view in the control of a character's eye directionand the point of view corresponding to the projected center and theposition of the virtual camera should be separate.

[0150] As a result, a plurality of polygons are connected as a singleobject, the polygons in a plurality of groups are interleaved incross-sectional groupings, and each group is textured with connectingpatterns, so that the diverse behavior of constantly moving spectatorscan be more realistically portrayed simply by moving the polygons intheir object units. Because they move in object units, software designcan be simplified with fewer commands, for example.

[0151] The behavioral control itself is simple, resulting in lowercomputing loads for such control. The control can be done with far lessdata to handle, while displaying behavior far more realistic than whenspectators are individually portrayed with polygons. As such, lessmemory capacity is needed to store the spectator data. Of course,spectator behavior can be displayed more realistically and immediatelywith less data than when such behavior is displayed by animation.

[0152] The process for fog control mentioned above is described belowwith reference to FIGS. 18 through 21. This fog control is a process inwhich one type of mask data having color values, as described above, issuperposed on image data. This affords a more realistic image displaywhich cannot be obtained by just reflecting on the screen the changes inbrightness accompanying changes in sunlight throughout the day usingonly conventional luminance data.

[0153] This process is executed by the CPU 1 as shown in FIG. 18, forexample. The process in FIG. 18 may also be executed by the VDP 5.

[0154] The CPU 1 first reads the current time, that is, the standardtime in which a player (individual playing the game device) is playingthe game device, from the real time clock 13 (S51). It is thendetermined whether or not the time deviates from the predetermined timezone serving as reference for daytime, evening, or night (S52). Thestandard time zones for daytime, evening, and night are determined asshown in FIG. 19, for example. For example, the daytime standard timezone is established at a relatively long 6:00 to 16:30, the evening timezone is established at 17:00 to 18:30, and the night standard time zoneis established at 19:30 to 5:30. The daytime standard time zone islonger because to avoid differences in game results due to changes inscreen brightness between players playing in the morning and playersplaying in the evening.

[0155] When YES in step S52, the predetermined fog data parameters forthe daytime, evening, and night standard time zones are read from ROM 2(S53). The three parameters are red, blue, and green fog color codes,offset values (indicating fog depth), and density (degree to which fogis applied relative to depth), and these parameters are predetermined soas to be suited to the standard time zones.

[0156] The CPU 1 then computes the fog data, and outputs the data in theform of mask data to the VDP 5 (S54, S55).

[0157] If NO in step S52, the deviation between the current time and thestandard time zones is calculated (S56). For example, when the time is5:45 in the morning, the deviation is 15 minutes exactly midway betweenthe night standard reference time zone and that for daytime.

[0158] The CPU 1 then reads the fog data parameters (R, G, B colorcodes, offset values, density) for the two standard time zones betweenwhich the deviant time falls (S57). When the time is 5:45, for example,the parameters for the night and daytime standard time zones are read.

[0159] The offset and density parameter values are corrected (S58). Forexample, when the time is 5:45, the offset values and density are themean values for ½ of the offset and density values of the night anddaytime standard time zones. When the time is closer to one of thestandard time zones, the values are averaged (corrected), with thevalues of the closer time zone given more importance.

[0160] The offset values and density are determined by such correctionwhen the time thus deviates from the standard time zone, and the fogdata is computed and output in the same manner as above (S54, S55).

[0161] This results in the real time display images which have beenfogged according to the state of sunlight assumed for the time duringwhich the game is being played by a player (individual playing the gamedevice). For example, when a game is played in the evening, thebackground beyond the playing field has darkish fogging (see the slantedlines in FIG. 20). When a game is played at night, for example, thebackground has darkish fogging and yellowish fogging from the shine ofmoon light, assuming the moon is out in the back ground (see slantedlines in FIG. 21).

[0162] It is thus possible to more realistically represent spectralchanges and the brightness of the light source, unlike cases in whichthe state of the sunlight (physical brightness) in the images portrayingthe playing field and its environment is displayed merely through thecontrol of the luminance as in the past. In particular, local brightnesssuch as in portions where the moon is out, for example, can be easier tocontrol because of the coverage of the color fog data. In the presentembodiment, the subtle brightness of standard time zones such as whenthe rising or setting sun is out can be processed based on the correctedparameters obtained using two standard time zones among those fordaytime, evening, and night.

[0163] That is, the color state is determined by preparing in advancethe color state corresponding to suitable color states for a daytime,evening, or night game, and by making corrections (specifically,processes for mixing color; luminance values corrected on the basis oftwo sets of standard values may also be added) based on standard valuesbetween daytime and evening, evening and night, or night and daytime forcolor states suited to the time in which the game is played. It is thusno longer difficult to play the game as the screen darkens, which iswhat happens when adjustments are made using only luminance values. Thepoint at which color adjustment begins (one standard value) and thepoint at which it ends (another standard value) are predetermined, andthe states which are suitable for games are set, so no advantages ordisadvantages are produced by the color state of the screen, no matterwhat time in which the game is played. That is, because of the verynature of the game, it is important that “no sense of unfairness isexperienced as a result of advantages or disadvantages caused by thetime zone in which the game isplayed^(T” when “color changes based on time changes” are presented, and the device in the present embodiment is able to deal with this. It is thus possible to provide images with better immediacy in portraying the brightness of the environment in which the playing field and its surroundings are enveloped.)

[0164] The aforementioned control of character's eye direction, controlof spectator behavior, and fog control need not necessarily be managedsimultaneously. Any one or two may be controlled.

[0165] A second embodiment of the present invention is described belowwith reference to FIGS. 23 through 58.

[0166]FIG. 23 illustrates the appearance of a video game machinefeaturing the use of an image processing device relating to anotherembodiment of the present invention. In the figure, the video gamemachine main unit 50 is roughly in the shape of a box, with boards andthe like for processing the game installed in the interior. Twoconnectors 60 a are provided on the font surface of the video gamemachine main unit 50, and game playing PADs 60 b are connected by cables60 c to the connectors 60 a. When two players play the game, both PADs60 b are used.

[0167] A cartridge I/F 50 a for connecting ROM cartridges and a CD-ROMdrive 50 b for reading CD-ROM are provided on the top of the vide gamemachine main unit 50. Although not shown in the figure, video outputterminals and audio output terminals are provided in the back of thevideo game machine main unit 50. The video output terminals areconnected by a cable 70 a to the video input terminals of a TV receiver80, and the audio output terminals are connected by a cable 70 b to theaudio input terminals of th TV receiver 80. Users operate the PAD 60 bin such video game machines to play the game while watching imagesprojected on the TV receiver 80.

[0168]FIG. 24 is a block diagram showing a schematic of the TB gamemachine in the present embodiment. The image processing device iscomposed of a CPU block 51 for controlling the entire system, a videoblock 52 for controlling the game screen display, a sound block 53 forgenerating sound effects and the like, a subs system 54 for reading theCD-ROM, and the like.

[0169] The CPU block 51 is composed of an SCU (system control unit) 100,a main CPU 101, an RAM 102, and ROM 103, a cartridge I/F 50 a, a subCPU104, a CPU bus 103, and the like. The main CPU 101 controls the entiresystem. The main CPU 101 has computing functions similar to that of aninternal DSP (digital signal processor), allowing application softwareto be rapidly executed. The RAM 102 is used as a work area for the mainCPU 101. An initial program or the like for initialization is written tothe ROM 103. The SCU 100 controls buses 105, 106, and 107 so as toensure smooth data input and output between the main CPU 101, VDP 120and 130, DSP 140, CPU 141, and the like. The SCU 100 has a DMAcontroller installed in the interior, allowing sprite data in the gameto be transmitted to the VRAM in the video block 52. Applicationsoftware for games and the like can thus be rapidly executed. Thecartridge 50 a is used to input application software provided in theform of an ROM cartridge.

[0170] The subCPU 104 is referred to as a SMPC (system manager andperipheral control), and has the function of collecting peripheral datafrom the PADs 60 b through the connectors 60 a in response to commandsfrom the main CPU 101. The main CPU 101 executes processes based onperipheral data received from the CPU 104. Any peripheral from amongPADs, joysticks, keyboards, and the like can be connected to theconnectors 60 a. The subCPU 104 has the functions of automaticallyrecognizing the type of peripheral connected to the connectors 60 a(main unit side terminals), and of collecting peripheral data accordingto the transmission mode corresponding to the type of peripheral.

[0171] The video block 52 is equipped with a VDP (video displayprocessor) 120 for imaging characters and the like consisting of videogame polygon data, and a VDP 130 for imaging background screens,synthesizing polygon image data and background images, clippingprocessing, and the like. The VDP 120 is connected to the VRAM 121, andframe buffers 122 and 123. The imaging data for the polygonsrepresenting the video game machine characters are sent from the mainCPU 101 through the SCU 100 to the VDP 120, and are written to the VRAM121. The imaging data written to the VRAM 121 is imaged by the imagingframe buffer 122 or 123 in the form of 16- or 8-bit/pixels, for example.The imaged data in the frame buffer 122 or 123 is sent to the VDP 130.Data controlling the imaging is sent from the main CPU 101 through theSCU 100 to the VDP 120. The VDP 120 executes the imaging processaccordingly.

[0172] The VDP 130 is connected to the VRAM 131, and image data outputfrom the VDP 130 is output to an encoder 160 through memory 132. Theencoder 160 generates image signals by adding synchronizing signals orthe like to the image data, and outputs them to the TV receiver 80. Thegame screen is thus displayed on the TV receiver 80.

[0173] The sound block 53 is composed of a DSP 140 for synthesizingsounds according to either PCM mode or FM mode, and a CPU 141 forcontrolling the DSP 140. The audio data synthesized by the DSP 140 isconverted to 2 channel signals by a D/A convertor 170, and is thenoutput to speakers 80 b.

[0174] The subsystem 54 is composed of a CD-ROM driver 50 b, CD I/F 180,CPU 181, MPEG Audio 182, MPEG Video 183, and the like. The subsystem 54has the function of reading application software provided in the form ofCD-ROM, and of reproducing animation. The CD-ROM drive 50 b reads datafrom the CD-ROM. The CPU 181 executes processes such as control of theCD-ROM drive 50 b and correcting errors in the data that is read. Thedata read from the CD-ROM is fed through the CD I/F 180, bus 106, andSCU 100 to the CPU 101, where it is used as application software. TheMPEG Audio 182 and MPEG Video 183 are devices for restoring data whichhas been compressed according to MPEG standards (motion picture expertgroup). Animation can be reproduced by using the MPEG audio 182 and MPEGvideo 183 to restore the MPEG compressed data written to CD-ROM.

[0175]FIG. 25 illustrates a case of a soccer game being played, as anexample of a game, in 3D virtual game space formed by a computer system.

[0176] In the figure, a soccer court is formed on the x-z a plane in 3Dvirtual space. The lengthwise direction (left-right direction) of thecourt is in the direction of the x axis, the breadthwise direction(depthwise direction) of the court is in the direction of the y axis,and the heightwise direction is in the direction of the z axis. Variousathlete objects not shown in the figure are situated on the court, andthe game device players control the movements of the character athletesby means of input devices. Line objects are described on the ground toform the soccer court. The game is relayed by a virtual camera (point ofview) which is situated to display circumstances in the visual field invirtual game space by means of coordinate conversion or the like on atwo-dimensional monitor screen.

[0177]FIGS. 26 and 27 illustrate perspectives in the present invention.In FIG. 26, line objects are arranged by a combination of polygons(hereinafter referred to as line polygons) forming lines on the ground,and a soccer court drawn by the lines is formed, as shown in FIG. 25.The lines are well displayed on the screen when the camera position ingame space is at an angle overlooking the field from above, but thesurface area of the lines in the screen diminishes as the vertical (yaxis) angle of the camera approaches the horizontal direction, and thelines gradually disappear from the monitor screen. Additionally, incases where the line polygons and camera face each other, that is, whenthe line polygon normal line vector and the camera's eye directionvector are parallel, it is sometimes possible for the line polygons tobecome so fine that they cannot be displayed on two-dimensionalprojection screens in which three-dimensional virtual space hasundergone coordinate conversion when the point of view is sufficientlyremote. This is disadvantageous in games which are played inside suchlines (or a court).

[0178] Thus, in the present invention, the positional coordinates ofsome of the vertices of line polygons are modified to increase thesurface area projected by the camera under conditions which make itdifficult for lines to be projected on the monitor screen. That is,

[0179] That is, in the reciprocal relation with the camera, the surfacearea of line polygons projected by the camera is increased by slightlyelevating, as shown in FIG. 27, the height position of vertices locatedin the depthwise direction, as viewed from the camera, of the linepolygons situated on the ground.

[0180]FIG. 28 is a flow chart illustrating the algorithm for such aprocess.

[0181] First, when line polygons (or line objects) are present in thevisual field of the camera viewing objects situated in virtual gamespace, a corresponding flag is established by the program not shown inthe figure. When this is determined in the main program (not shown infigure), a process for preventing the lines from disappearing isexecuted (S102, YES).

[0182] It is first determined whether the vertices of the line polygonsare located away from or toward the camera. A method for this, as shownin FIG. 29, is to calculate the distance 11 between the camera andvertex P1 and distance 12 between the camera and vertex P3, and todetermine the further and nearer vertices based on the magnitude of thetwo distances.

[0183] Another method, as shown in FIG. 30, is to compare the angles θ1and θ3 of the vertices P1 and P3 and the angles Ø1 and Ø3 of the camerato determine the further and nearer vertices P1 and P3. Although eitherof these two methods can be used in the present embodiment, the latteris more advantageous because there are fewer calculations for thehardware than in the former method.

[0184] The latter method for comparing angles is used to describe thedetermination of the further and nearer vertices of the line polygons insteps S104 through S110 below.

[0185] The data of a line polygon is read from an object table not shownin the figure which gives the object groups situated in the scene(S104). FIG. 31 is of an example of line polygon data, where, forexample, coordinate values (x_(n), z_(n)) of a world coordinate systemas well as predetermined angles and the like for determining further andnearer vertices are correlated in the data for polygon vertices P1through P4.

[0186] As shown in FIG. 30, the current position of the camera in theworld coordinate system (x-z plane) and the angle Øn in the vertex Pndirection of a line polygon seen from the camera position are then read.The angle Øn can be determined by a trigonometric function from thecoordinates of the line polygon vertex Pn and the coordinates of thecamera position (S106).

[0187] The line polygon vertex and camera angle are then compared(S108). In FIG. 30, for example, the predetermined angle for vertex PIis 90 degrees, and the predetermined angle for vertex P3 is 270 degrees.When the angle Ø1 from the x axis of the eye direction vector betweenthe camera and vertex P1 is 120 degrees, then 120 degrees−90 degrees=30degrees<90 degrees (where 90 degrees is the reference value fordetermination in this case) (S108), allowing it to be determined as thevertex on the depthwise edge of the polygon (S110).

[0188] When the angle Ø3 from the x axis of the eye direction vectorbetween the camera and vertex P3 is 150 degrees, then 150 degrees−270degrees=ABS (120 degrees)>90 degrees (where 90 degrees is the referencevalue for determination in this case, and ABS is the absolute value)(S108), allowing it to be determined as the vertex on the nearer edge ofthe line (S110).

[0189] When the vertex Pn is the nearer edge of a line object, no heightadjustment is carried out for vertex Pn, and the data for the next linepolygon vertex is read (S110, NO).

[0190] When the vertex Pn is the nearer edge of a line object (S110,YES), it is determined whether or not the distance to vertex Pn is 10 mor less. If 10 m or less (S112, YES), that is, when the camera is nearthe line, the line is normally visible on the screen, so the height ofthe vertex Pn is not adjusted, and the data for the next line polygonvertex is read (S112, NO).

[0191] When the distance to the vertex Pn is more than 10 m (S112, NO),that is, when the camera is remote from the line, the line is usuallydifficult to see, so the value in the y axis direction (heightwisedirection) in the coordinate data for the vertex Pn on the further edgeof the line is increased a certain amount to raise the further edge ofthe line polygon up from the ground (S114). This process is carried outfoe each of the vertices of all the line polygons in the screen (S116).

[0192] As a result, the further edges of the line objects situated invirtual game space are raised up, as shown in FIG. 27, allowing them tobe easily seen from the camera.

[0193] A third embodiment of the present invention is described below.The third invention involves dividing the game field (soccer ground)into prescribed areas, determining the area in which the ball islocated, and adjusting the camera angle so that the direction in whichthe ball is advancing (direction in which the player wants to look) canbe readily seen.

[0194]FIGS. 32 through 34 illustrate the directions in which game deviceplayers move and desirable camera directions when moving in suchdirections.

[0195] First, as shown in FIG. 25, the camera basically moves along thesidelines and is directed in the player direction. Of course, the cameracan move into the field to following the game.

[0196] When players controlled by the game device players move in thedirection to and away from the viewer (z axis direction) in the x -yplane (FIG. 32a), the camera is directed in the z axis direction (FIG.32b).

[0197] When the players controlled by the game device players move inthe left direction (−x axis direction) in the x-y plane (FIG. 33a), thecamera is turned from the z axis direction to a specific angle, such as−15 degrees, to increase the screen display in the area in the directionin which the ball is advancing (FIG. 33b). Here, the angle measured inthe clockwise direction (positive direction) from the z axis is apositive value, and angles measured in the counterclockwise direction(negative direction) are negative values.

[0198] When players controlled by the game device players move in theright direction (x axis direction) in the x-y plane (FIG. 34a), thecamera is turned from the z axis direction to a specific angle, such as15 degrees, to increase the screen display in the area in the directionin which the ball is advancing (FIG. 34b).

[0199] An example in which the direction of the camera point of view isdetermined by combining the camera angle adjustment and the game fieldarea is described with reference to FIGS. 35 and 36.

[0200] The main routine for lateral camera angle adjustment is firstexecuted according to prescribed timing (conditions) determined in themain program not shown in the figure, and it is determined whether themain point of view of the camera is on the player side or the ball side(S132).

[0201] When it is on the player side (S132, player side), it isdetermined whether or not the main point of view is a prescribeddistance, such as 8 m or less, from the soccer court penalty area(S134). When within 8 m (S134, YES), opponents and fellow team matesgather in the vicinity of the penalty area, with a greater opportunityto pass or shoot (FIG. 37), so the camera tilts about −15 degreesrelative to the z axis to afford a better view of the vicinity of thepenalty area (S136, FIG. 38).

[0202] When more than 8 m from the penalty area (S134, NO), thedirection in which the player advances is determined (S138). When theplayer is moving toward the viewer (FIG. 39) or away from the viewer(FIG. 40), the angle of the camera in the x-z plane is 0 degreesrelative to the player (S140, FIG. 41). When the player is moving to theleft (FIG. 42), the angle of the camera relative to the player is −15degrees from the z axis (S142, FIG. 43). When the player is moving tothe right (FIG. 44), the angle of the camera relative to the player is15 degrees from the z axis (S144, FIG. 45).

[0203] When the ball is the main point of view of the camera (S132, ballside), it is determined whether or not the distance between the ball andplayer is a prescribed distance, such as 15 m or more (S146). If 15 m ormore (S146, YES, FIG. 46), the camera angle is determined so that theeye direction vector from the ball toward the player is at an angle of20 degrees from the z axis (S154, FIG. 47). When the position betweenthe player and ball is the opposite, relative to the z axis, the cameraangle is determined so that the eye direction vector from the ball tothe player is −20 degrees (S154, FIG. 48).

[0204] When the distance between the ball and player is not a specificdistance such as 15 m or more (S146, NO), it is determined whether ornot the main point of view of the camera is within 8 m of a penalty area(S148). When the main point of view of the camera is within 8 m of thepenalty area (S148, YES, FIG. 49), the eye direction vector of thecamera is set to an angle of −15 degrees (FIG. 50). When the positionbetween the ball an player is the opposite, as shown in FIG. 48, thedirection of the camera is set 15 degrees from the z axis.

[0205] When the distance between the ball and player is within 15 m, andthe main point of view of the camera is not with 8 m of the penalty area(S148, NO, FIG. 51), the eye direction vector of the camera is set to 0degrees relative to the ball (0 degrees relative to the z axis) (FIG.52). When these processes are concluded, the system returns to the mainprogram.

[0206] Occasionally, it becomes difficult to play at right angles to thedirection in which the player on the screen is moving in cases whereplayer movement in the x and z directions is input by the game deviceplayer using an input device such as a pad or joystick if the cameraangle from the z axis is too great when the camera moves along thesidelines. A camera angle of about 15 degrees is thus advantageous.

[0207] The camera angle of the player in the x-z plane is thus adjustedaccording to areas in the game field, affording a better view in thedirection in which the ball is advancing.

[0208] Vertical (y axis direction) camera angle adjustment is describedbelow. FIG. 53 is a flow chart of the process for adjusting the verticalcamera angle, which is executed according to prescribed timing(conditions) determined in the main program not shown in the figure. Thecamera height position is usually set, but not limited, to a height ofabout 10 m. The main routine, as shown in FIG. 54, establishes the angleat which the camera tracks the game field according to game areas. Thatis, the position of the main point of view of the camera is determined(S162). When the player is the main point of view (S162, player), it isdetermined whether or not the main point of view is near the penaltyarea (S164). When the main point of view is not near the penalty area(S164, NO), the camera direction is determined so that the eye directionvector of the camera is −8 degrees from the z axis, to afford arelatively broad range of vision (S166). Here, when the camera looksdown, the angle is negative, when it looks up, the angle is positive,and when it is level, the angle is 0. When the main point of view isnear a penalty area (S164, YES), the camera direction is determined sothat the eye direction vector of the camera is −11 degrees from the zaxis (S168). This allows the camera to give a better view overlookingthe field, resulting in images with a better sense of depth anddimension.

[0209] When the ball is the main point of view (S162, ball), it isdetermined whether or not the main point of view is near a penalty area(S170). When the main point of view is not near the penalty area (S170,NO), the camera direction is determined so that the line of sigh vectorof the camera is −11 degrees from the z axis (S166). When the main pointof view is near the penalty area (S170, YES), the camera direction isset so that the eye direction vector of the camera is −13 degrees fromthe z axis (S174).

[0210] Upon the conclusion of these processes, the system returns to themain program.

[0211]FIG. 55 is a flow chart of the camera zoom adjustment. When it isdetermined in the main program that camera zoom adjustment is needed,the process moves to the main routine.

[0212] First, it is determined whether or not the main point of view ofthe camera is near a penalty area (S182). When it is near a penaltyarea, the camera zooms down to a prescribed distance from the main pointof view (S184). This allows the entire penalty area to be seen.

[0213] When the main point of view of the camera is not near the penaltyarea (S182, NO) and the player is outside the screen (S186, YES), thecamera zooms down to project the player in the screen (S188). As shownin FIG. 56, when the player is in the screen (S186, NO) and the playeris in ¾ of the screen (S190, YES), the camera zooms up to a prescribeddistance from the main point of view (S190). This allows close ups ofplayers in situations where a fixed range is not visible. When theplayer is projected on the screen but is in ¾ of the screen (S190, NO),the distance between the camera dn main point of view is maintained(S194).

[0214]FIG. 57 is a flow chart of another example enabling the display ofobjects which should be prevented from disappearing on the screen, suchas the aforementioned line polygons.

[0215] In the figure, attribute data indicating that an object is to beprevented from disappearing is added to the data of polygons whichshould be prevented from disappearing When object groups in the visualfield of the virtual camera are displayed on the screen, the computersystem determines whether or not there are polygons which are to beprevented from disappearing in the visual field (S202).

[0216] When there are polygons which should be prevented fromdisappearing, such as line polygons (S202, YES), a program that preventspolygons from disappearing is actuated. That is, as shown in FIG. 58, aunit eye direction vector is determined from the main point of view ofthe camera and the position of the camera (S204). The unit normal linevector is determined from the data for polygons which are to beprevented from disappearing (S206). The angle between the unit eyedirection vector and the unit normal line vector is determined. This canbe determined as the inner product of the unit eye direction vector andthe unit normal line vector (S208). The polygon vertex coordinate valuesare adjusted so that the angle is at a prescribed angle (S210). Theprocess from step 204 to step 210 is executed for each polygon that isto be prevented from disappearing in the visual field. Here, step 202corresponds to means for preventing such disappearance, steps 204through 208 correspond to angle computing means, and step 310corresponds to polygon tilting means.

[0217] This allows lines and the like that are indispensable for a gameto be prevented from disappearing.

[0218] The present invention is not limited to soccer games, and isapplicable for a variety of games in which a ground or court isdescribed by lines, such as tennis, baseball, basket ball, volley ball,Rubgy, and American football.

[0219] Camera zooming is thus adjusted according to area and displaystatus.

[0220] A program for executing the aforementioned image processingdevice and for executing the method for displaying images on a computersystem may be provided as a recording on data recording media such asCD-ROMs, DVD-ROMs, and ROM cassettes.

[0221] The embodiment described with reference to FIGS. 8 through 17 isnot limited to embodiments in which the surfaces of polygons A throughD″ are mapped with textures of spectators facing the playing field, thatis, examples of display objects displayed in three-dimensional virtualspace serving as the game space. For example, among the textures mappedto polygon surfaces, portions of the background other than displayobjects modeled on spectators may be used as transparent bit textures,and portions of the display objects may be used as opaque bit textures.

[0222]FIG. 59 is a schematic of such textures. The opaque bit texturearea includes the spectator display objects 300 and surrounding portions301 as needed. FIG. 60 is an example of texture related to anotherspectator embodiment. The background 302 is similarly transparent bits,and the characters 304 are opaque bits. This texture is mapped topolygons other than polygons mapped with the texture in FIG. 59, andpolygons mapped with the texture in FIG. 60 are arranged in front of thepolygons mapped with the texture in FIG. 59, that is, more on thevirtual point of view side. FIG. 61 shows a state in which thesetextures are layered, that is, superposed, as shown in FIGS. 8 through17. The characters 304 in FIG. 60 are superposed on the transparent background portion of FIG. 59. Accordingly, when the polygons in FIGS. 59and 60 are superposed, spectators with the two textures are displayed onthe screen while blended, grouped, and superposed. When spectators whichare these polygon characters are superposed, the spectators toward thebottom in three-dimensional space, that is, spectators of polygonshaving the lowest priority, are under polygons having the highestpriority, and are not displayed on the screen.

[0223] Spectator movements can be reproduced or simulated in the samemanner as the previous embodiment of spectator behavior by moving aplurality of polygons mapped with such textures along planesperpendicular or otherwise intersecting the direction in which theplurality of polygons are superposed, or in a direction intersecting thevirtual camera facing polygons A through D″ in three-dimensional space,or in a direction intersecting the direction in which they aresuperposed, as shown in FIGS. 8 through 17.

[0224]FIGS. 62 and 63 are of a case in which the polygons 400 describedin FIG. 59 the polygons 402 described in FIG. 60 are superposed, whereFIG. 62 shows the polygons 400 moving up, and FIG. 63 shows the polygons402 moving up.

[0225] Thus, in the present invention, movements such as that of severaldisplay objects moving as in the case of spectators around a soccer gamefield, movements of groups consisting of several display objects, andmovements in cases where several display objects are preferably dividedinto several blocks and are moved while the blocks are controlled(movements of animals and insects) can be created more efficiently. Suchmovements are produced in specific modes, such as in the case of soccergames and when athletes competing over a ball make a goal. It bearsrepeating that the textures described here may be picture data includingcharacters such as spectators and background (clouds, waves, etc.). Inaddition, instead of constructing the background portions in FIG. 59with transparent textures, texture of a single may be used, and thetexture in FIG. 60 may be constructed of texture with another colordistinguishable from this single color. Furthermore, the backgroundportion of FIG. 60 may be made of a single color texture, and thebackground portion of FIG. 59 can be used as it is with transparentcolors, while at least the profiles of the characters in FIG. 59 are notthe aforementioned single color. In the case of FIGS. 8 through 17, thepolygons were arranged in, but are not limited to, positions so as to begradually inclining upward in virtual space, so the polygons can also bearranges in a virtually level plane.

[0226] In the aforementioned embodiments, the eyes of a character weredirected at a target when it was determined whether or not the relationto the game contents or the positional relation such as the distancebetween characters and the target having a relation through the game tothe aforementioned characters matched certain conditions, so that when acharacter competed while dribbling a ball in a soccer game, for example,the character looked in (surveyed) other directions to look for teammates or kicking zones, allowing the behavior of actual soccercontestants to be more realistically simulated, providing more naturalmovements, and achieving greater realism and immediacy.

[0227] The control of the point of view provides effects such as 1)affecting the strategies used in the game and the level of gamedifficulty, and 2) making it easier to understand and play situations orpoints to which the ball can (should) be passed based on the behavior ofcharacters in the possession of the ball in ball games.

[0228] In the embodiments, a plurality of polygons mapped with texturemodeled on a plurality of spectators are virtually superposed, and theplurality of polygons are moved in a direction intersecting thedirection in which they are superposed, so that the variegated movements(more realistic behavior) of individual spectators can be represented.Software design is simplified, the computing load is reduced, and memorycapacity can be reduced. These and other demands can be simultaneouslyaddressed, and game immediacy can be further enhanced.

[0229] Also in the embodiments, the time of the game being played by agame device player is sensed, and the screen colors for the images aredetermined according to that time by corrections based on screen colorspreviously optimized for games, so that presentations with changes inthe screen colors are added according to the time in which the game isbeing played, allowing the screen colors to be constantly maintained insuch a way as to avoid interfering with the game. It is also possible toavoid the drawbacks that occur when the screen color state is adjustedusing only the luminance, as in the past, and it is furthermore possibleto more consistently and accurately make the changes in brightnessthroughout the day compatible with the color state of the displayscreen, further enhancing game immediacy.

[0230] Polygons which are difficult to see in virtual space due to thecamera position sometimes occur in games which develop inthree-dimensional virtual space, so in another embodiment, line objectsdrawn on the ground, for example, are prevented from disappearing bymeans of image processing.

[0231] Yet another embodiment affords a game device for adjusting thecamera position, camera direction, range of visual field, and the likeaccording to the direction in which the objects move or game areas,resulting in a screen that makes games easier to play.

1. An image processing device that displays the behavior of charactersmodeled on opponents in virtual three-dimensional space, wherein saidimage processing device is characterized by comprising: determinationmeans for determining whether or not there exists a certain situation inwhich the relation to the game contents or the positional relationbetween characters and a target having a relation through the game tosaid characters matches certain conditions; and eye direction controlmeans for directing the eyes of said characters to said objects when thedetermination means has determined said certain situation exists.
 2. Theimage processing device according to claim 1 , wherein said game is asoccer game, and said object is a ball in said soccer game.
 3. The imageprocessing device according to claim 1 , wherein said eye directioncontrol means includes means for rotating and controlling the torsos andwaists of said characters with the rotation of the heads of saidcharacters.
 4. The image processing device according to claim 1 ,wherein said determination means includes means for computing the anglefrom said characters to the target based on coordinate values of saidcharacters and said target in said virtual three-dimensional space. 5.The image processing device according to claim 1 , wherein there are aplurality of said objects, and said determination means includesdetermination means for determining to which of said plurality oftargets the eye direction should be directed according to said gamesituation.
 6. An image processing method for displaying the behavior ofcharacters modeled on opponents in virtual three-dimensional space,wherein said image processing method is characterized in that adetermination is made as to whether or not there exists a certainsituation in which the relation to the game contents or the positionalrelation between characters and a target having a relation through thegame to said characters matches certain conditions, and the eyes of saidcharacters are directed to said target when it has been determined thatthe certain situation exists.
 7. An image processing method fordisplaying the behavior of characters modeled on opponents in virtualthree-dimensional space, wherein said image processing method ischaracterized in that a determination is made as to whether or notcertain conditions have been established while said character is made toexecute a first behavior, and said character is made to execute a secondbehavior when said certain conditions have been established, so thatdata of the developing game situation is suggested to the player.
 8. Animage processing device for displaying the behavior of display objectsin virtual three-dimensional space, wherein said image processing deviceis characterized by comprising: a plurality of polygons in whichtextures are individually mapped to a plurality of display objects, saidplurality of polygons being virtually superposed; and polygonoscillation means for moving the plurality of polygons along planesintersecting the directions in which the polygons are superposed.
 9. Theimage processing device according to claim 8 , wherein said plurality ofpolygons are virtually superposed, while the plurality of polygons thatform the various plurality of objects are interleaved according to thesequence of objects, and said polygon oscillation means is a means forperiodically moving said plurality of objects while synchronized andlinked with each object.
 10. The image processing method according toclaim 9 , wherein said moving direction is the vertical or lateraldirection of said polygons.
 11. An image processing method fordisplaying the behavior of display objects in virtual three-dimensionalspace, wherein said image processing method is characterized in that aplurality of polygons individually mapped with textures modeled on aplurality of display objects are virtually superposed, and saidplurality of polygons are moved in directions intersecting thedirections in which the polygons are superposed.
 12. An image processingdevice for simulating and displaying games in virtual three-dimensionalspace, wherein said image processing device is characterized bycomprising: sensing means for sensing the time of said game being playedby a player; and adjusting means for adjusting the screen colors of saidimages according to the time sensed by the sensing means.
 13. The imageprocessing device according to claim 12 , wherein said adjusting meanscomprises memory means by which values for screen colors of at least twostandard time zones established for situations suited to the game arestored in the form of various reference values; and data generatingmeans which, when the time sensed by said sensing means is within eitherof said standard time zones, generates masking data for the game displayscreen based on the corresponding one of said reference values, andwhich, when said time is not within either of said standard time zones,generates said masking data based on information for the screen colorstate interpolated on the basis of the two reference values temporallyprior to and following said time in said at least two reference values.14. An image processing method for simulating and displaying games invirtual three-dimensional space, wherein said image processing method ischaracterized by sensing the time of said game being played by theplayer, and by adjusting the screen color of said images according tosaid time.
 15. An image processing method in which a display objectmodeled on a living creature in virtual three-dimensional space isdisplayed on a display screen, as the perspective is changed from agiven point of view, wherein said image processing method ischaracterized by the steps of: comparing the position of an imaginarypoint determined in said virtual space and the position of said displayobject; determining whether or not the results of said comparison matchcertain conditions set by a program; and establishing said imaginarypoint as the main point of view of said display object when the resultsof said match said certain conditions.
 16. An image processing method inwhich a display object modeled on a living creature in virtualthree-dimensional space is displayed on a display screen, as theperspective is changed from a given point of view, wherein said imageprocessing method is characterized by the steps of: comparing theposition of a plurality of imaginary points determined in said virtualspace and the position of said display object; and selecting saidimaginary point as the main point of view of said display object.
 17. Animage processing device for situating objects in virtual space formed bya computer system, developing a game while controlling the movements ofsaid objects according to input control and set rules, and displayingcircumstances in said virtual space as the screen seen from a virtualcamera, wherein said image processing device is characterized bycomprising: polygons situated on a reference plane serving as thereference in said virtual space; determination means for determining thepositional relation between said polygons and said virtual camera; andpolygon tilting means for tilting said polygons, according to theresults of the determination, so as to increase the surface area of saidpolygons seen from said virtual camera.
 18. The image processing deviceaccording to claim 17 , wherein said reference plane is the ground, andsaid polygons are polygons forming lines situated on said ground. 19.The image processing device according to claim 17 , wherein saidpolygons are quadrilateral, and said polygon tilting means modifies thecoordinate values of the vertices on one of the sides of mutually facingsides of said polygons.
 20. An image processing device for situatingobjects in virtual space formed by a computer system, developing a gamewhile controlling the movements of said objects according to inputcontrol and set rules, and displaying circumstances in said virtualspace as the screen seen from a virtual camera, wherein said imageprocessing device is characterized by comprising: determination meansfor determining whether or not said objects are in a specific area insaid virtual space; and camera angle adjusting means for adjusting theangle of said virtual camera based on the results of said determination.21. The image processing device according to claim 20 , wherein saidcamera angle adjusting means adjusts the angle of said virtual camerabased on the results of said determination and the direction in whichsaid objects are moving.
 22. The image processing device according toclaim 20 or 21 , wherein said camera angle adjusting means adjusts theangle of said virtual camera in at least one of either the lateral andvertical directions in said virtual space.
 23. An image processingdevice for situating objects in virtual space formed by a computersystem, developing a game while controlling the movements of saidobjects according to input control and set rules, and displayingcircumstances in said virtual space as the screen seen from a virtualcamera, wherein said image processing device is characterized bycomprising: determination means for determining whether or not saidobjects are in a specific area in said virtual space; and zoom adjustingmeans for adjusting the range of the field of vision of said virtualcamera based on the results of said determination.
 24. An imageprocessing device having an image generating display means forconverting virtual space constructed with a three-dimensional modelconsisting of a plurality of polygons to two-dimensional images seenfrom a virtual camera in any position, and displaying them on a displaydevice, wherein said image processing device comprises: angle computingmeans for computing the angle between an eye direction vector showingthe direction in which said virtual camera is facing and a normal linevector showing the orientation of the plane of certain polygons situatedin said virtual space; and polygon tilting means for changing thecoordinate values of the vertices of said polygons, so that the anglecomputed by said angle computing means assumes a certain value.
 25. Animage processing device having image generating display means forgenerating two-dimensional images that reveal, from any point of view,virtual space constructed with a three-dimensional model consisting of aplurality of polygons, and for displaying them on a display device, saidpolygons comprising nondisappearing polygons which have attributespreventing them from disappearing and which contain data for operating aprogram to prevent polygons from disappearing; said disappearanceprevention program comprising position determination means fordetermining the positional relation between said nondisappearingpolygons and said point of view, and coordinate modification means formodifying the coordinate values of the vertices of said nondisappearingpolygons according to the results of the determination by said positiondetermination means; and said image processing device furthermorecomprising disappearance prevention execution means for executing saiddisappearance prevention program when the polygons visualized on saiddisplay device are said nondisappearing polygons.
 26. Data recordingmedia on which has been recorded a program for allowing a computersystem to function as an image processing device according to any ofclaims 1 through 5, 8, 9, 12, 13, and 17 through
 25. 27. An imageprocessing device for displaying circumstances in virtualthree-dimensional space in the form of images seen from a camera,wherein said image processing device comprises: polygons situated on areference plane serving as reference in said virtual three-dimensionalspace; determination means for determining the positional relationbetween said polygons and said virtual camera; and polygon tilting meansfor tilting said polygons, according to the results of the determinationby said determination means, so as to increase the surface area of saidpolygons seen from the virtual camera.
 28. An image processing devicefor displaying circumstances in virtual three-dimensional space in theform of images seen from a virtual camera, wherein said image processingdevice comprises: polygons situated on a reference plane serving asreference in said virtual three-dimensional space; determination meansfor determining the positional relation between said polygons and saidvirtual camera; and polygon tilting means for tilting said polygons,according to the results of the determination by said determinationmeans, so as to allow the vertices in the interior, relative to saidvirtual camera, of said polygons to stand out from said reference plane,while centered on the vertices in the front, relative to said virtualcamera, of said polygons.
 29. A game machine, characterized bycomprising an image processing device according to claim 27 or 28 , forexecuting a game by situating objects in said virtual three-dimensionalspace and by controlling said objects according to player input controland set rules.
 30. The game device according to claim 29 , characterizedin that said game is a game in which objects are situated in a gamefield formed on a reference plane, and said polygons are polygonsforming lines described on said game field.
 31. An image processingdevice for displaying circumstances in said virtual three-dimensionalspace in the form of images seen from a virtual camera, wherein saidimage processing device comprises: polygons situated in said virtualthree-dimensional space; determination means for determining thepositional relation between said polygons and said virtual camera; andpolygon tilting means for tilting said polygons, according to theresults determined by said determination means, so as to increase thesurface area of said polygons seen from the virtual camera.
 32. Theimage processing device according to claim 27 , 28 , or 31,characterized in -that said polygons are polygons that show lines.
 33. Agame device, characterized by comprising an image processing deviceaccording to claim 31 , for executing a game by situating objects insaid virtual three-dimensional space and by controlling said objectsaccording to player input control and set rules.
 34. The game deviceaccording to claim 33 , characterized in that said game is a game inwhich objects are situated on a plane, and said polygons are polygonsforming lines described on said plane.